2010 Cadillac CTS Sedan AWD V6-3.6L Page 564
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the RF door handle antenna.
2. Ignition ON, verify a test lamp does not illuminate between the signal circuit terminal A and ground.
瀚慖f the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the RCDLR.
3. Install a DMM between the signal circuit terminal A and the low reference circuit terminal B. Set the DMM to capture AC voltage using the
MIN MAX function.
4. Perform the Passenger Front Exterior Zone special functions test. Verify the DMM captured an AC voltage signal.
瀚慖f an AC voltage was not captured, test the signal circuit and the low reference circuit for a short to ground or an open/high resistance. If
the circuits test normal, replace the RCDLR.
5. If all circuits test normal, test or replace the RF door handle assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
* Front Side Door Outside Handle Replacement (Front and Rear Doors with ATH) (See: Body and Frame/Doors, Hood and
Trunk/Doors/Front Door/Front Door Handle/Front Door Exterior Handle/Service and Repair)Front Side Door Outside Handle Replacement
(Front Door with ATH) (See: Body and Frame/Doors, Hood and Trunk/Doors/Front Door/Front Door Handle/Front Door Exterior
Handle/Service and Repair)Front Side Door Outside Handle Replacement (Without ATH) (See: Body and Frame/Doors, Hood and
Trunk/Doors/Front Door/Front Door Handle/Front Door Exterior Handle/Service and Repair)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for RCDLR replacement, setup, and programming
B3121
DTC B3121
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC B3121 00
- Keyless Entry Antenna 3 Performance - Rear Compartment Antenna
Diagnostic Fault Information
